Aqueous humor nitric oxide levels in patients with Behcet disease

Purpose: The purpose of this study was to quantify aqueous humor nitric oxide levels in patients with Behcet uveitis and age-matched controls to assess how nitric oxide is involved in this ocular condition. Methods: Samples of aqueous humor were collected from 11 patients with Behcet uveitis who were undergoing cataract surgery. Sampling was done by paracentesis at the beginning of the operation. Similar samples were collected from 20 age-matched normal patients (controls). For each sample, we used the spectrophotometric method based on the Griess reaction to determine the amount of nitrite, which is the stable metabolite of nitric oxide. Results: The amount of nitrite in aqueous humor samples from patients with Behcet disease was above the detection limit in 8 of 11 cases; the mean level +/- SEM was 2.13 +/- 0.621 mumol/L. Levels in the control group were below the detection limit in all cases (<0.08 mumol/L). There was a statistically significant difference between the aqueous humor nitrite levels in patients with Behcet disease and those in controls (P = 0.00002). Conclusions: Aqueous humor nitric oxide levels are elevated in patients with a history of Behcet disease.